Add directory as second argument to dpkg-deb to ensure file is named package_version_arch.deb

Author: brbsix

Makefile

@@ -1,7 +1,7 @@
 .PHONY: deb install userinstall uninstall useruninstall
 
 deb:
-	dpkg-deb -z8 -Zgzip --build vagrant-bash-completion
+	dpkg-deb -z8 -Zgzip --build vagrant-bash-completion .
 
 install:
 	install -m 0644 vagrant-bash-completion/etc/bash_completion.d/vagrant /etc/bash_completion.d/vagrant